title: Subclinical brain injury caused by H5N1 influenza virus infection.
abstract: Although H5N1 influenza A viruses can cause systemic infection, their neurotropism and long-term effects on the central nervous system (CNS) are not fully understood. We assessed H5N1viral invasion of the CNS and its long-term effects in a ferret model. An H5N1 virus caused nonsuppurative encephalitis, which lasted for 3 months without neurologic signs. Further, another H5N1 virus caused nonsuppurative vasculitis with brain hemorrhage. Three-dimensional analysis of viral distribution in the brain identified the olfactory system as a major route for brain invasion. The efficient growth of virus in the upper respiratory tract may thus facilitate viral brain invasion.
authors.affiliation: Division of Zoonosis, Department of Microbiology and Infectious Disease, Graduate School of Medicine, Kobe University, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, Japan.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Shinya
authors.forename: Akiko
authors.initials: A
authors.lastname: Makino
authors.forename: Masato
authors.initials: M
authors.lastname: Hatta
authors.forename: Shinji
authors.initials: S
authors.lastname: Watanabe
authors.forename: Jin Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Hatta
authors.forename: Peng
authors.initials: P
authors.lastname: Gao
authors.forename: Makoto
authors.initials: M
authors.lastname: Ozawa
authors.forename: Quynh Mai
authors.initials: QM
authors.lastname: Le
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kawaoka
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D018792:Encephalitis, Viral / Q000473:pathology* / Q000821:virology*; D005289:Ferrets; D053124:Influenza A Virus, H5N1 Subtype / Q000472:pathogenicity*; D009833:Olfactory Pathways / Q000821:virology; D009976:Orthomyxoviridae Infections / Q000150:complications* / Q000473:pathology* / Q000821:virology